1. Field of the Invention:
The present invention relates to the electrochemical oxidation of cerium 3.sup.+ to cerium 4.sup.+, in emulsion, and, more especially, to the electrochemical oxidation of solutions of cerous sulfate.
2. Description of the Prior Art:
It is known to this art, from FR 2,570,087, to electrochemically oxidize cerium 3.sup.+ to cerium 4.sup.+ in a sulfuric medium.
The process described in this '087 patent is characterized in that, in a first circulation loop, the sulfuric solution is treated in a first anode compartment of an electrolytic cell comprising a first anode compartment and a cathode compartment separated therefrom by a first cationic membrane, and wherein a first fraction of the solution treated in said anode compartment is recycled back into said anode compartment; and that, in a second circulation loop, a second fraction of the solution is treated in a second anode compartment of said electrolytic cell, also separated from said cathode compartment by a second cationic membrane, and a portion of the solution treated in this manner is recycled into the second anode compartment and the remaining portion of the solution is separated as final product. An electrolyte is circulated in the cathode compartment, a portion of he electrolyte issuing from this compartment being combined with the solution circulating in the first loop, and the remaining portion is recycled into said cathode compartment.
The electrolytic cell thus comprises two anode compartments, a single cathode department situated between the two anode compartments, and two cationic membranes separating each of the anode compartments from the cathode compartment.
This type of apparatus makes it possible to obtain high "Faraday" yields and a high cerium 3.sup.+ conversion ratio.
However, use of such a cell is disadvantageous when solutions with a very low cerium 3.sup.+ concentration are treated, because the electrode face surfaces must be considerably increased in light of the low current density, such that the size of the installation becomes quite large.